Actual rules state that you don't can't get close to real life airlines, but nothing about game airlines.
Although this sounds stupid IRL, in the game customer would see you as very different (like Delta and United for example.)
So even if I create an airline based in ATL called Amereecan Citilinks, it still works... we are different.
The reason why you can't use real airlines names is to detach the game from reality, as well as to avoid unwanted promotion for a given airline.
hope this clarifies
Enjoy your game